U.S. patent application number 16/411472 was filed with the patent office on 2019-11-21 for photosensitive resin composition, photosensitive dry film, and pattern forming process.
This patent application is currently assigned to Shin-Etsu Chemical Co., Ltd.. The applicant listed for this patent is Shin-Etsu Chemical Co., Ltd.. Invention is credited to Hideto Kato, Hitoshi Maruyama, Michihiro Sugo.
Application Number | 20190354014 16/411472 |
Document ID | / |
Family ID | 66448366 |
Filed Date | 2019-11-21 |
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United States Patent
Application |
20190354014 |
Kind Code |
A1 |
Maruyama; Hitoshi ; et
al. |
November 21, 2019 |
PHOTOSENSITIVE RESIN COMPOSITION, PHOTOSENSITIVE DRY FILM, AND
PATTERN FORMING PROCESS
Abstract
A photosensitive resin composition comprising (A) a silphenylene
and polyether structure--containing polymer and (B) a photoacid
generator is coated onto a substrate to form a photosensitive resin
coating which has improved substrate adhesion, a pattern forming
ability, crack resistance, and reliability as protective film.
Inventors: |
Maruyama; Hitoshi;
(Annaka-shi, JP) ; Kato; Hideto; (Annaka-shi,
JP) ; Sugo; Michihiro; (Annaka-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shin-Etsu Chemical Co., Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Shin-Etsu Chemical Co.,
Ltd.
Tokyo
JP
|
Family ID: |
66448366 |
Appl. No.: |
16/411472 |
Filed: |
May 14, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 77/46 20130101;
G03F 7/0752 20130101; C09D 183/14 20130101; G03F 7/0757 20130101;
G03F 7/168 20130101; C08G 77/70 20130101; G03F 7/40 20130101; G03F
7/0045 20130101; H01L 24/13 20130101; C08G 77/80 20130101; G03F
7/325 20130101; G03F 7/38 20130101; G03F 7/0382 20130101; C08G
77/54 20130101; H01L 24/11 20130101; C09D 183/12 20130101; G03F
7/038 20130101; G03F 7/2004 20130101; H01L 2224/13147 20130101;
C08G 77/52 20130101; H01L 2224/11618 20130101; C08G 77/60 20130101;
H01L 2224/11462 20130101 |
International
Class: |
G03F 7/075 20060101
G03F007/075; G03F 7/004 20060101 G03F007/004; G03F 7/038 20060101
G03F007/038; G03F 7/40 20060101 G03F007/40; C08G 77/60 20060101
C08G077/60; H01L 23/00 20060101 H01L023/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 17, 2018 |
JP |
2018-095370 |
Claims
1. A photosensitive resin composition comprising (A) a silphenylene
and polyether structure-containing polymer comprising repeating
units having the following formulae (1) to (4), and (B) a photoacid
generator, ##STR00014## wherein X.sup.1 is a divalent group having
the following formula (X1), X.sup.2 is a divalent group having the
following formula (X2), X.sup.3 is a divalent group having the
following formula (X3), X.sup.4 is a divalent group having the
following formula (X4), and p, q, r and s are numbers in the range:
0<p<1, 0.ltoreq.q<1, 0.ltoreq.r<1, 0s.ltoreq.1,
0<q+r+s<1, and p+q+r+s=1, ##STR00015## wherein R.sup.1 and
R.sup.2 are each independently hydrogen or a C.sub.1-C.sub.8
monovalent hydrocarbon group, R.sup.3 and R.sup.4 are each
independently hydrogen or methyl, a.sup.1 and a.sup.2 are each
independently an integer of 1 to 6, and n is an integer of 0 to
100, ##STR00016## wherein Y.sup.1 is a single bond, methylene,
propane-2,2-diyl, 1,1,1,3,3,3-hexafluoropropane-2,2-diyl or
fluorene-9,9-diyl, R.sup.11 and R.sup.12 are each independently
hydrogen or methyl, R.sup.13 and R.sup.14 are each independently a
C.sub.1-C.sub.4 alkyl or alkoxy group, b.sup.1 and b.sup.2 are each
independently an integer of 0 to 7, and c.sup.1 and c.sup.2 are
each independently an integer of 0 to 2, ##STR00017## wherein
Y.sup.2 is a single bond, methylene, propane-2,2-diyl,
1,1,1,3,3,3-hexafluoropropane-2,2-diyl or fluorene-9,9-diyl,
R.sup.21 and R.sup.22 are each independently hydrogen or methyl,
R.sup.23 and R.sup.24 are each independently a C.sub.1-C.sub.4
alkyl or alkoxy group, d.sup.1 and d.sup.2 are each independently
an integer of 0 to 7, and e.sup.1 and e.sup.2 are each
independently an integer of 0 to 2, ##STR00018## wherein R.sup.31
and R.sup.32 are each independently hydrogen or methyl, and f.sup.1
and f.sup.2 are each independently an integer of 0 to 7.
2. The photosensitive resin composition of claim 1, further
comprising (C) a crosslinker.
3. The photosensitive resin composition of claim 2 wherein the
crosslinker is at least one compound selected from the group
consisting of an amino condensate modified with formaldehyde or
formaldehyde-alcohol, a phenol compound having on the average at
least two methylol or alkoxymethyl groups in the molecule, and an
epoxy compound having on the average at least two epoxy groups in
the molecule.
4. The photosensitive resin composition of claim 1, further
comprising (D) a solvent.
5. The photosensitive resin composition of claim 1, further
comprising (E) a quencher.
6. A photosensitive resin coating obtained from the photosensitive
resin composition of claim 1.
7. A photosensitive dry film comprising a support and the
photosensitive resin coating of claim 6 thereon.
8. A pattern forming process comprising the steps of: (i) coating
the photosensitive resin composition of claim 1 onto a substrate to
form a photosensitive resin coating thereon, (ii) exposing the
photosensitive resin coating to radiation to define exposed and
unexposed regions, and (iii) developing the exposed resin coating
in a developer to dissolve away the unexposed region of the resin
coating and to form a pattern of the resin coating.
9. A pattern forming process comprising the steps of: (i') using
the photosensitive dry film of claim 7 to form the photosensitive
resin coating on a substrate, (ii) exposing the photosensitive
resin coating to radiation to define exposed and unexposed regions,
and (iii) developing the exposed resin coating in a developer to
dissolve away the unexposed region of the resin coating and to form
a pattern of the resin coating.
10. The pattern forming process of claim 8, further comprising (iv)
post-curing the patterned resin coating resulting from development
step (iii) at a temperature of 100 to 250.degree. C.
11. The photosensitive resin composition of claim 1 which is to
form a coating for protecting electric and electronic parts.
12. The photosensitive resin composition of claim 1 which is used
as a resist material in the step of forming copper interconnects by
plating.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35
U.S.C. .sctn. 119(a) on Patent Application No. 2018-095370 filed in
Japan on May 17, 2018, the entire contents of which are hereby
incorporated by reference.
TECHNICAL FIELD
[0002] This invention relates to a photosensitive resin
composition, a photosensitive dry film, and a pattern forming
process.
BACKGROUND ART
[0003] In the prior art, photosensitive protective films for
semiconductor devices and photosensitive insulating films for
multilayer printed circuit boards are formed of photosensitive
polyimide compositions, photosensitive epoxy resin compositions,
photosensitive silicone compositions, and the like. As the
photosensitive material applied for the protection of such
substrates and circuits, Patent Document 1 discloses a
photosensitive silicone composition. This photosensitive silicone
composition is curable at low temperature and forms a coating which
is fully reliable with respect to moisture resistant adhesion and
other properties, but is less resistant against chemicals such as
photoresist strippers having a high dissolving power, typically
N-methyl-2-pyrrolidone (NMP).
[0004] To overcome the problem, Patent Document 2 proposes a
photosensitive silicone composition based on a silphenylene
structure-containing silicone polymer. This composition is improved
in chemical resistance against photoresist strippers and the like,
but still has the problem that the cured coating peels from the
substrate or cracks in a thermal cycling test (repeating 1,000
cycles a test of holding at -25.degree. C. for 10 minutes and
holding at 125.degree. C. for 10 minutes). A further improvement in
reliability is desired.
CITATION LIST
[0005] Patent Document 1: JP-A 2002-088158 (USP 6,590,010, EP
1186624)
[0006] Patent Document 2: JP-A 2008-184571 (USP 7,785,766, EP
1953183)
DISCLOSURE OF INVENTION
[0007] An object of the invention is to provide a photosensitive
resin composition and a photosensitive dry film, which give a cured
resin coating or resin layer that can be processed in thick film
form to define a fine size pattern, has improved film properties
including crack resistance and adhesion to substrates for use in
electronic parts and semiconductor devices and supports for use in
circuit boards, and is thus reliable as a protective film for
electric and electronic parts. Another object is to provide a
pattern forming process using the foregoing.
[0008] The inventors have found that a silphenylene and polyether
structure-containing polymer having crosslinking groups or
crosslinking reaction-susceptible reactive sites in the molecule
functions to provide a sufficient film-forming ability; that a
composition comprising the polymer is used to form a photosensitive
resin coating having a wide range of thickness; and that the
photosensitive resin coating has improved adhesion to substrates,
electronic parts and semiconductor devices, a pattern forming
ability, crack resistance, electric insulation, and reliability as
insulating protective film, and is thus useful as a protective film
for electric and electronic parts and a resist material for
plating.
[0009] In one aspect, the invention provides a photosensitive resin
composition comprising (A) a silphenylene and polyether
structure-containing polymer comprising repeating units having the
following formulae (1) to (4), and (B) a photoacid generator
##STR00001##
Herein X.sup.1 is a divalent group having the following formula
(X1), X.sup.2 is a divalent group having the following formula
(X2), X.sup.3 is a divalent group having the following formula
(X3), X.sup.4 is a divalent group having the following formula
(X4), and p, q, r and s are numbers in the range: 0<p<1,
0.ltoreq.q<1, 0.ltoreq.r<1, 0.ltoreq.s<1, 0<q+r+s<1,
and p+q+r+s=1.
##STR00002##
Herein R.sup.1 and R.sup.2 are each independently hydrogen or a
C.sub.1-C.sub.8 monovalent hydrocarbon group, R.sup.3 and R.sup.4
are each independently hydrogen or methyl, a.sup.1 and a.sup.2 are
each independently an integer of 1 to 6, and n is an integer of 0
to 100.
##STR00003##
Herein Y.sup.1 is a single bond, methylene, propane-2,2-diyl,
1,1,1,3,3,3-hexafluoropropane-2,2-diyl or fluorene-9,9-diyl,
R.sup.11 and R.sup.12 are each independently hydrogen or methyl,
R.sup.13 and R.sup.14 are each independently a C.sub.1-C.sub.4
alkyl or alkoxy group, b.sup.1 and b.sup.2 are each independently
an integer of 0 to 7, and c.sup.1 and c.sup.2 are each
independently an integer of 0 to 2.
##STR00004##
Herein Y.sup.2 is a single bond, methylene, propane-2,2-diyl,
1,1,1,3,3,3-hexafluoropropane-2,2-diyl or fluorene-9,9-diyl,
R.sup.21 and R.sup.22 are each independently hydrogen or methyl,
R.sup.23 and R.sup.24 are each independently a C.sub.1-C.sub.4
alkyl or alkoxy group, d.sup.1 and d.sup.2 are each independently
an integer of 0 to 7, and e.sup.1 and e.sup.2 are each
independently an integer of 0 to 2.
##STR00005##
Herein R.sup.31 and R.sup.32 are each independently hydrogen or
methyl, and f.sup.1 and f.sup.2 are each independently an integer
of 0 to 7.
[0010] The photosensitive resin composition may further comprise
(C) a crosslinker, (D) a solvent and/or (E) a quencher. The
crosslinker is typically at least one compound selected from the
group consisting of an amino condensate modified with formaldehyde
or formaldehyde-alcohol, a phenol compound having on the average at
least two methylol or alkoxymethyl groups in the molecule, and an
epoxy compound having on the average at least two epoxy groups in
the molecule.
[0011] Typically, the photosensitive resin composition is to form a
coating for protecting electric and electronic parts, or is used as
a resist material in the step of forming copper interconnects by
plating.
[0012] In another aspect, the invention provides a photosensitive
resin coating obtained from the photosensitive resin composition
defined above.
[0013] In a further aspect, the invention provides a photosensitive
dry film comprising a support and the photosensitive resin coating
thereon.
[0014] In a still further aspect, the invention provides a pattern
forming process comprising the steps of (i) coating the
photosensitive resin composition defined above onto a substrate to
form a photosensitive resin coating thereon, (ii) exposing the
photosensitive resin coating to radiation to define exposed and
unexposed regions, and (iii) developing the exposed resin coating
in a developer to dissolve away the unexposed region of the resin
coating and to form a pattern of the resin coating.
[0015] In a still further aspect, the invention provides a pattern
forming process comprising the steps of (i') using the
photosensitive dry film defined above to form the photosensitive
resin coating on a substrate, (ii) exposing the photosensitive
resin coating to radiation to define exposed and unexposed regions,
and (iii) developing the exposed resin coating in a developer to
dissolve away the unexposed region of the resin coating and to form
a pattern of the resin coating.
[0016] In either embodiment, the pattern forming process may
further include the step of (iv) post-curing the patterned resin
coating resulting from development step (iii) at a temperature of
100 to 250.degree. C.
ADVANTAGEOUS EFFECTS OF INVENTION
[0017] The photosensitive resin composition and the photosensitive
dry film have many advantages of photosensitive material and can be
readily processed in thick film form to define a fine size pattern.
The cured resin coating obtained from the photosensitive resin
composition has improved film properties including chemical
resistance against photoresist strippers and plating baths,
adhesion to substrates, electronic parts, semiconductor devices,
and supports for circuit boards, mechanical properties, and
electric insulation, and is thus fully reliable as an insulating
protective film. The cured resin coating also has crack resistance
and is thus useful as a protective film-forming material for
electric and electronic parts (such as circuit boards,
semiconductor devices and display units) and a resist material for
plating.
DESCRIPTION OF PREFERRED EMBODIMENT
[0018] As used herein, the notation (Cn-Cm) means a group
containing from n to m carbon atoms per group.
Photosensitive Resin Composition
[0019] One embodiment of the invention is a photosensitive resin
composition comprising (A) a silphenylene and polyether
structure-containing polymer, and (B) a photoacid generator.
(A) Silphenylene and Polyether Structure-Containing Polymer
[0020] Component (A) is a polymer containing a silphenylene
structure and a polyether structure, specifically comprising
repeating units having the following formulae (1) to (4). For
simplicity sake, this polymer is referred to as Polymer A, and the
repeating units having the formulae (1) to (4) are referred to as
repeating units (1) to (4), respectively. Polymer A has
crosslinking groups such as epoxy and hydroxyl groups or
crosslinking reaction-susceptible reactive sites in the
molecule.
##STR00006##
[0021] In formula (1), X.sup.1 is a divalent group having the
formula (X1).
##STR00007##
[0022] In formula (X1), R.sup.1 and R.sup.2 are each independently
hydrogen or a C.sub.1-C.sub.8 monovalent hydrocarbon group, R.sup.3
and R.sup.4 are each independently hydrogen or methyl, a.sup.1 and
a.sup.2 are each independently an integer of 1 to 6, preferably 1
to 4, and more preferably 1 or 2, and n is an integer of 0 to 100,
preferably 1 to 50, and more preferably 5 to 30.
[0023] The C.sub.1-C.sub.8 monovalent hydrocarbon groups may be
straight, branched or cyclic, and include, for example, monovalent
aliphatic hydrocarbon groups such as C.sub.1-C.sub.8 alkyl groups
and C.sub.2-C.sub.8 alkenyl groups and monovalent aromatic
hydrocarbon groups such as C.sub.6-C.sub.8 aryl groups and C.sub.7
or C.sub.8 aralkyl groups.
[0024] Examples of the C.sub.1-C.sub.8 alkyl group include methyl,
ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl,
sec-butyl, tert-butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl,
cyclohexyl, n-heptyl, and n-octyl. Examples of the alkenyl group
include vinyl, propenyl, butenyl, and pentenyl. Examples of the
aryl group include phenyl, 2-methylphenyl, 3-methylphenyl,
4-methylphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, and
dimethylphenyl. Examples of the aralkyl group include benzyl and
phenethyl.
[0025] R.sup.1 and R.sup.2 are preferably hydrogen or
C.sub.1-C.sub.8 alkyl groups, more preferably hydrogen or
methyl.
[0026] In formula (X1), the alkylene oxide units with subscript n
may be randomly or alternately arranged, or plural blocks of the
same alkylene oxide units may be included.
[0027] In formula (2), X.sup.2 is a divalent group having the
formula (X2).
##STR00008##
[0028] In formula (X2), Y.sup.1 is a single bond, methylene,
propane-2,2-diyl, 1,1,1,3,3,3-hexafluoropropane-2,2-diyl or
fluorene-9,9-diyl, R.sup.11 and R.sup.12 are each independently
hydrogen or methyl, R.sup.13 and R.sup.14 are each independently a
C.sub.1-C.sub.4 alkyl or alkoxy group, b.sup.1 and b.sup.2 are each
independently an integer of 0 to 7, and c.sup.1 and c.sup.2 are
each independently an integer of 0 to 2.
[0029] The C.sub.1-C.sub.4 alkyl group may be straight, branched or
cyclic, and examples thereof include methyl, ethyl, n-propyl,
isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,
and cyclobutyl. The C.sub.1-C.sub.4 alkoxy group may be straight,
branched or cyclic, and examples thereof include methoxy, ethoxy,
n-propyloxy, isopropyloxy, cyclopropyloxy, n-butyloxy, isobutyloxy,
sec-butyloxy, tert-butyloxy, and cyclobutyloxy.
[0030] In formula (3), X.sup.3 is a divalent group having the
formula (X3).
##STR00009##
[0031] In formula (X3), Y.sup.2 is a single bond, methylene,
propane-2,2-diyl, 1,1,1,3,3,3-hexafluoropropane-2,2-diyl or
fluorene-9,9-diyl, R.sup.21 and R.sup.22 are each independently
hydrogen or methyl, R.sup.23 and R.sup.24 are each independently a
C.sub.1-C.sub.4 alkyl or alkoxy group, d.sup.1 and d.sup.2 are each
independently an integer of 0 to 7, and e.sup.1 and e.sup.2 are
each independently an integer of 0, 1 or 2. Examples of the
C.sub.1-C.sub.4 alkyl or alkoxy group are as exemplified in the
description of formula (X2).
[0032] In formula (4), X.sup.4 is a divalent group having the
formula (X4).
##STR00010##
[0033] In formula (X4), R.sup.31 and R.sup.32 are each
independently hydrogen or methyl, and f.sup.1 and f.sup.2 are each
independently an integer of 0 to 7.
[0034] In formulae (1) to (4), p, q, r and s indicative of contents
(molar fractions) of repeating units (1), (2), (3), and (4) in
Polymer A, respectively, are numbers in the range: 0<p<1,
0.ltoreq.q<1, 0.ltoreq.r<1, 0.ltoreq.s<1, 0<q+r+s<1,
and p+q+r+s=1. From the aspects of film formation or handling, p,
q, r and s are preferably numbers in the range:
0.1.ltoreq.p.ltoreq.0.9, 0.ltoreq.q.ltoreq.0.9,
0.ltoreq.r.ltoreq.0.9, 0.ltoreq.s.ltoreq.0.9, and
0.1.ltoreq.q+r+s.ltoreq.0.9, more preferably
0.2.ltoreq.p.ltoreq.0.8, 0.ltoreq.q.ltoreq.0.8,
0.ltoreq.r.ltoreq.0.8, 0.ltoreq.s.ltoreq.0.8, and
0.2.ltoreq.q+r+s.ltoreq.0.8, with the proviso that p+q+r+s=1. The
repeating units (1) to (4) may be arranged either randomly or
blockwise.
[0035] Polymer A preferably has a weight average molecular weight
(Mw) of 3,000 to 500,000, more preferably 5,000 to 200,000.
Polymers with Mw in the range are fully soluble in most common
organic solvents. It is noted throughout the disclosure that Mw is
measured by gel permeation chromatography (GPC) versus polystyrene
standards using tetrahydrofuran as the elute.
[0036] Polymer A may be composed of randomly or alternately
arranged repeating units (1) to (4) or plural blocks each
consisting of units of the same type.
[0037] Polymer A exerts a sufficient film-forming function in the
photosensitive resin composition. A photosensitive resin coating
obtained from the composition comprising Polymer A has improved
adhesion to substrates, electronic parts, semiconductor devices and
the like, a pattern forming ability, and crack resistance.
Preparation of Polymer A
[0038] Polymer A may be prepared by addition polymerization of a
compound having the formula (5), a compound having the formula
(X1'), and at least one compound selected from a compound having
the formula (X2'), a compound having the formula (X3'), and a
compound having the formula (X4'), all shown below, in the presence
of a metal catalyst.
##STR00011##
Herein Y.sup.1, Y.sup.2, R.sup.1 to R.sup.4, R.sup.11 to R.sup.14,
R.sup.21 to R.sup.24, R.sup.31, R.sup.32, a.sup.1, a.sup.2,
b.sup.1, b.sup.2, c.sup.1, c.sup.2, d.sup.1, d.sup.2, e.sup.1,
e.sup.2, f.sup.1, f.sup.2 and n are as defined above.
[0039] Examples of the metal catalyst used herein include platinum
group metals alone such as platinum (including platinum black),
rhodium and palladium; platinum chlorides, chloroplatinic acids and
chloroplatinates such as H.sub.2PtCl.sub.4.xH.sub.2O,
H.sub.2PtCl.sub.6.xH.sub.2O, NaHPtCl.sub.6.xH.sub.2O,
KHPtCl.sub.6.xH.sub.2O, Na.sub.2PtCl.sub.6.xH.sub.2O,
K.sub.2PtCl.sub.4.xH.sub.2O, PtCl.sub.4. xH.sub.2O, PtCl.sub.2 and
Na.sub.2HPtCl.sub.4.xH.sub.2O, wherein x is preferably an integer
of 0 to 6, more preferably 0 or 6; alcohol-modified chloroplatinic
acids as described in U.S. Pat. No. 3,220,972; chloroplatinic
acid-olefin complexes as described in U.S. Pat. No. 3,159,601, U.S.
Pat. No. 3,159,662 and U.S. Pat. No. 3,775,452; supported catalysts
comprising platinum group metals such as platinum black and
palladium on supports of alumina, silica and carbon; rhodium-olefin
complexes; chlorotris(triphenylphosphine)rhodium (known as
Wilkinson's catalyst); and complexes of platinum chlorides,
chloroplatinic acids and chloroplatinates with vinyl-containing
siloxanes, specifically vinyl-containing cyclosiloxanes.
[0040] The catalyst is used in a catalytic amount, which is
preferably 0.001 to 0.1% by weight of platinum group metal based on
the total weight of the reactants for polymerization reaction. In
the polymerization reaction, a solvent may be used if desired.
Suitable solvents are hydrocarbon solvents such as toluene and
xylene. With respect to polymerization conditions, the
polymerization temperature is preferably selected in a range of 40
to 150.degree. C., more preferably 60 to 120.degree. C., such that
the catalyst may not be deactivated and the polymerization be
completed within a short time. While the polymerization time varies
with the type and amount of monomers, the polymerization reaction
is preferably completed within about 0.5 to about 100 hours, more
preferably about 0.5 to about 30 hours for preventing moisture
entry into the polymerization system. After the completion of
polymerization reaction, the solvent if any is distilled off,
obtaining Polymer A.
[0041] The reaction procedure is not particularly limited. The
preferred procedure is by first mixing a compound having formula
(X1') with one or more compounds selected from a compound having
formula (X2'), a compound having formula (X3'), and a compound
having formula (X4'), heating the mixture, adding a metal catalyst
to the mixture, and then adding a compound having formula (5)
dropwise over 0.1 to 5 hours.
[0042] The reactants are preferably combined in such amounts that a
molar ratio of hydrosilyl groups on the compound having formula (5)
to the total of alkenyl groups on the compounds having formulae
(X1'), (X2'), (X3'), and (X4') may range from 0.67/1 to 1.67/1,
more preferably from 0.83/1 to 1.25/1. The Mw of Polymer A may be
controlled using a molecular weight control agent such as a
monoallyl compound (e.g., o-allylphenol), monohydrosilane (e.g.,
triethylhydrosilane) or monohydrosiloxane.
(B) Photoacid Generator
[0043] The photoacid generator (PAG) as component (B) is typically
a compound which is decomposed to generate an acid upon exposure to
light with a wavelength of 190 to 500 nm, the generated acid
serving as a curing catalyst. Since the photosensitive resin
composition of the invention is highly compatible with the PAG, the
PAG may be selected from a wide variety of such compounds. Typical
PAGs include onium salts, diazomethane derivatives, glyoxime
derivatives, .beta.-ketosulfone derivatives, disulfone derivatives,
nitrobenzyl sulfonate derivatives, sulfonic acid ester derivatives,
imido-yl sulfonate derivatives, oxime sulfonate derivatives, imino
sulfonate derivatives, and triazine derivatives.
[0044] From the standpoint of photo-cure, the PAG (B) is preferably
used in an amount of 0.05 to 20 parts by weight, and more
preferably 0.05 to 5 parts by weight per 100 parts by weight of
component (A). When the amount of the PAG is at least 0.05 part, it
may generate a sufficient amount of acid for crosslinking reaction
to proceed. As long as the amount of the PAG is up to 20 parts, any
increase of the light absorption by the PAG itself is prevented and
a lowering of transparency is avoided. The PAGs may be used alone
or in admixture of two or more.
(C) Crosslinker
[0045] Preferably the photosensitive resin composition further
comprises (C) a crosslinker. The crosslinker functions to
facilitate pattern formation and to increase the strength of the
cured composition.
[0046] Preferably, the crosslinker is selected from amino
condensates modified with formaldehyde or formaldehyde-alcohol,
nitrogen-containing compounds such as melamine, guanamine,
glycoluril and urea compounds, having on the average at least two
methylol and/or alkoxymethyl groups in the molecule, phenol
compounds having on the average at least two methylol or
alkoxymethyl groups in the molecule, and epoxy compounds having on
the average at least two epoxy groups in the molecule. These
compounds may be used alone or in admixture.
[0047] Examples of the amino condensate modified with formaldehyde
or formaldehyde-alcohol include melamine condensates modified with
formaldehyde or formaldehyde-alcohol, and urea condensates modified
with formaldehyde or formaldehyde-alcohol.
[0048] Suitable melamine compounds include hexamethylolmelamine,
hexamethoxymethylmelamine, trimethoxymethylmonomethylolmelamine,
dimethoxymethylmonomethylolmelamine, trimethylolmelamine, and
hexamethoxyethylmelamine. Suitable guanamine compounds include
tetramethylolguanamine, tetramethoxymethylguanamine and
tetramethoxyethylguanamine.
[0049] Suitable glycoluril compounds include
tetramethylolglycoluril and tetramethoxymethylglycoluril. Suitable
urea compounds include tetramethylolurea, tetramethoxymethylurea,
and tetramethoxyethylurea.
[0050] Examples of the phenol compound having on the average at
least two methylol or alkoxymethyl groups in a molecule include
(2-hydroxy-5-methyl)-1,3-benzenedimethanol and
2,2',6,6'-tetramethoxymethylbisphenol A.
[0051] Examples of the epoxy compound having on the average at
least two epoxy groups in a molecule include bisphenol epoxy resins
such as bisphenol A epoxy resins and bisphenol F epoxy resins,
novolak epoxy resins such as phenol novolak epoxy resins and cresol
novolak epoxy resins, triphenol alkane epoxy resins, biphenyl epoxy
resins, dicyclopentadiene-modified phenol novolak epoxy resins,
phenol aralkyl epoxy resins, biphenyl aralkyl epoxy resins,
naphthalene ring-containing epoxy resins, glycidyl ester epoxy
resins, cycloaliphatic epoxy resins, and heterocyclic epoxy
resins.
[0052] The crosslinker (C) is preferably used in an amount of 0.5
to 50 parts, and even more preferably 1 to 30 parts by weight per
100 parts by weight of component (A). At least 0.5 part of
component (C) ensures sufficient cure upon light exposure. As long
as the amount of component (C) is up to 50 parts, the proportion of
Polymer A in the resin composition is not reduced, allowing the
cured composition to exert its effects to the full extent. The
crosslinkers may be used alone or in admixture.
(D) Solvent
[0053] The photosensitive resin composition may further comprise a
solvent as component (D). The solvent used herein is not
particularly limited as long as the foregoing components (A) to
(C), and component (E) and additives to be described later are
soluble.
[0054] Preferred are organic solvents in which the foregoing
components are fully soluble. Illustrative, non-limiting, examples
of the organic solvent include ketones such as cyclohexanone,
cyclopentanone and methyl-2-n-pentylketone; alcohols such as
3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol,
and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl
ether, ethylene glycol monomethyl ether, propylene glycol monoethyl
ether, ethylene glycol monoethyl ether, propylene glycol dimethyl
ether, and diethylene glycol dimethyl ether; and esters such as
propylene glycol monomethyl ether acetate (PGMEA), propylene glycol
monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl
acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate,
tert-butyl acetate, tert-butyl propionate, propylene glycol
mono-tert-butyl ether acetate, and y-butyrolactone. These solvents
may be used alone or in admixture. Of these solvents, preferred are
ethyl lactate, cyclohexanone, cyclopentanone, PGMEA,
.gamma.-butyrolactone, and mixtures thereof, in which the PAG is
most soluble.
[0055] From the standpoints of compatibility and viscosity of the
resin composition, the amount of the solvent (D) used is preferably
50 to 2,000 parts, more preferably 50 to 1,000 parts, and even more
preferably 50 to 100 parts by weight per 100 parts by weight of
components (A) and (B) combined.
(E) Quencher
[0056] The photosensitive resin composition may further contain a
quencher as component (E). The quencher used herein is preferably a
compound capable of suppressing the rate of diffusion when the acid
generated by the PAG diffuses within the resin coating. The
inclusion of the quencher improves resolution, suppresses changes
in sensitivity following exposure and reduces substrate and
environment dependence, as well as improving the exposure latitude
and the pattern profile.
[0057] Examples of the quencher include primary, secondary, and
tertiary aliphatic amines, mixed amines, aromatic amines,
heterocyclic amines, nitrogen-containing compounds with carboxyl
group, nitrogen-containing compounds with sulfonyl group,
nitrogen-containing compounds with hydroxyl group,
nitrogen-containing compounds with hydroxyphenyl group, alcoholic
nitrogen-containing compounds, amide derivatives, and imide
derivatives.
[0058] From the standpoint of sensitivity, the amount of the
quencher (E) is preferably 0 to 3 parts by weight, more preferably
0.01 to 1 part by weight per 100 parts by weight of component (A).
The quenchers may be used alone or in admixture of two or more.
Other Additives
[0059] Besides the aforementioned components, the photosensitive
resin composition may include optional additives. A typical
additive is a surfactant which is commonly used for improving the
coating characteristics.
[0060] Preferred surfactants are nonionic surfactants, for example,
fluorochemical surfactants such as perfluoroalkyl polyoxyethylene
ethanols, fluorinated alkyl esters, perfluoroalkylamine oxides, and
fluorinated organosiloxane compounds. These surfactants are
commercially available. Illustrative examples include Fluorad.RTM.
FC-430 from 3M, Surflon.RTM. S-141 and S-145 from AGC Seimi
Chemical Co., Ltd., Unidyne.RTM. DS-401, DS-4031, and DS-451 from
Daikin Industries Ltd., Megaface.RTM. F-8151 from DIC Corp., and
X-70-093 from Shin-Etsu Chemical Co., Ltd. Preferred surfactants
are Fluorad FC-430 and X-70-093.
[0061] The surfactant is preferably used in an amount of 0.01 to 5
parts by weight, more preferably 0.1 to 3 parts by weight per 100
parts by weight of component (A). The surfactants may be used alone
or in admixture.
[0062] Another useful additive is a silane coupling agent, which is
effective for further increasing the adhesion of the resin
composition to an adherend. Suitable silane coupling agents include
epoxy-containing silane coupling agents and aromatic
group-containing aminosilane coupling agents. The silane coupling
agent may be used alone or in admixture. Although the amount of the
silane coupling agent used is not particularly limited, it is
preferably 0.01 to 5% by weight of the resin composition.
[0063] The photosensitive resin composition of the invention is
prepared in any desired way. For example, it may be prepared by
agitating and mixing the aforementioned components and optionally
passing the mixture through a filter to remove solids.
[0064] From the photosensitive resin composition, a resin coating
may be formed to a wide range of thickness. From the resin coating,
a pattern having fine feature size and perpendicularity may be
formed by the pattern forming process to be described below.
[0065] The photosensitive resin composition is advantageously used,
for example, as a film-forming material for semiconductor device
protective film, interconnection protective film, coverlay film,
solder mask, and TSV dielectric film, an adhesive between
substrates in three-dimensional laminates, and a resist material
for plating.
Pattern Forming Process Using Photosensitive Resin Composition
[0066] Another embodiment of the invention is a pattern forming
process comprising the steps of: [0067] (i) coating the
photosensitive resin composition onto a substrate to form a
photosensitive resin coating thereon, [0068] (ii) exposing the
photosensitive resin coating to radiation to define exposed and
unexposed regions, and [0069] (iii) developing the exposed resin
coating in a developer to dissolve away the unexposed region of the
resin coating and to form a pattern of the resin coating.
[0070] First, in step (i), the photosensitive resin composition is
coated onto a substrate to form a photosensitive resin coating
thereon. Examples of the substrate include silicon wafers, TSV
silicon wafers, silicon wafers which have been thinned by back side
polishing, plastic substrates, ceramic substrates, and substrates
having a metal coating of Ni or Au wholly or partly on the surface
by ion sputtering or plating.
[0071] The coating technique may be any well-known technique, for
example, dipping, spin coating, roll coating or the like. The
coating weight may be selected as appropriate for a particular
purpose, preferably so as to form a photosensitive resin coating
having a thickness of 1 to 400 .mu.m, more preferably 5 to 200
.mu.m.
[0072] A pre-wetting technique of dispensing a solvent dropwise on
a substrate prior to coating of the resin composition may be
employed for the purpose of making the coating thickness on the
substrate more uniform. The type and amount of the solvent
dispensed dropwise may be selected for a particular purpose. For
example, alcohols such as isopropyl alcohol (IPA), ketones such as
cyclohexanone, and glycols such as propylene glycol monomethyl
ether are preferred. The solvent used in the photosensitive resin
composition may also be used.
[0073] At this point, the coating may be prebaked to volatilize off
the solvent and the like, if necessary, for efficient photo-cure
reaction. Prebake may be performed, for example, at 40 to
140.degree. C. for 1 minute to about 1 hour.
[0074] Next, in step (ii), the photosensitive resin coating is
exposed to radiation to define exposed and unexposed regions. The
exposure radiation is generally of wavelength 1 to 600 nm,
preferably 10 to 600 nm, more preferably 190 to 500 nm. Examples of
radiation in the wavelength range include radiation of various
wavelengths from radiation-emitting units, specifically UV
radiation such as g-line, h-line or i-line, and deep UV (248 nm,
193 nm). Among these, radiation of wavelength 248 to 436 nm is
preferred. An appropriate exposure dose is 10 to 10,000
mJ/cm.sup.2.
[0075] Exposure may be made through a photomask. The photomask may
be, for example, one perforated with a desired pattern. Although
the material of the photomask is not particularly limited, a
material capable of shielding radiation in the above wavelength
range, typically chromium is preferred.
[0076] The next step may be post-exposure bake (PEB) which is
effective for enhancing development sensitivity. PEB is preferably
performed at 40 to 150.degree. C. for 0.5 to 10 minutes. The
exposed region of the resin coating is crosslinked by PEB to form
an insolubilized pattern which is insoluble in a solvent as
developer.
[0077] The exposure or PEB is followed by the step (iii) of
developing the exposed resin coating in a developer to dissolve
away the unexposed region of the resin coating and to form a
pattern of the resin coating. The preferred developers are organic
solvents including alcohols such as IPA, ketones such as
cyclohexanone, and glycols such as propylene glycol monomethyl
ether. The solvent used in the photosensitive resin composition is
also useful. Development is effected in a conventional manner, for
example, by dipping the exposed coating in the developer. The
development is followed by washing, rinsing and drying if
necessary. In this way, a resin coating having the desired pattern
is obtained.
[0078] In step (iv), the patterned coating may be post-cured in an
oven or hot plate at a temperature of preferably 100 to 250.degree.
C., more preferably 150 to 220.degree. C. The photosensitive resin
composition ensures that a resin coating having improved film
properties is obtained from post-cure even at a relatively low
temperature around 200.degree. C. The post-cure is effective for
increasing the crosslinking density of the resin coating and
removing any residual volatile matter. The resulting coating has
augmented adhesion to substrates, heat resistance, mechanical
strength, good electric properties, bond strength, and reliability.
A post-cure temperature in the range of 100 to 250.degree. C. is
preferred for acquiring the above properties. The resin coating as
post-cured has a thickness of 1 to 400 .mu.m, preferably 5 to 200
.mu.m.
[0079] Although the pattern forming process has been described, it
is sometimes unnecessary to form a pattern. When it is simply
desired to form a uniform film, for example, the same process as
above may be followed except that in step (ii), the resin coating
is exposed to radiation of suitable wavelength directly, i.e.,
without the photomask.
Photosensitive Dry Film
[0080] A further embodiment of the invention is a photosensitive
dry film comprising a support and the photosensitive resin coating
of the photosensitive resin composition thereon.
[0081] The photosensitive dry film (support+photosensitive resin
coating) is solid, and the photosensitive resin coating contains no
solvent. This eliminates the risk that bubbles resulting from
volatilization of solvent are left within the resin coating and
between the resin coating and the rugged substrate surface. An
appropriate thickness range exists for the resin coating when
planarity and step coverage on rugged substrate surface and a
substrate lamination spacing are taken into account. It is
preferred from the standpoints of planarity, step coverage, and
substrate lamination spacing that the photosensitive resin coating
have a thickness of 5 to 500 .mu.m, more preferably 20 to 350
.mu.m.
[0082] Furthermore, the viscosity and fluidity of the
photosensitive resin coating are closely correlated. As long as the
photosensitive resin coating has a proper range of viscosity, it
exhibits a sufficient fluidity to fill deeply even in a narrow gap
or it softens to enhance the adhesion to the substrate.
Accordingly, from the standpoint of fluidity, the photosensitive
resin coating should preferably have a viscosity in the range of 10
to 5,000 Pas, more preferably 30 to 2,000 Pas, and even more
preferably 50 to 300 Pas at a temperature of 80 to 120.degree. C.
It is noted that the viscosity is measured by a rotational
viscometer.
[0083] The photosensitive dry film has the advantage that when
tightly attached to a substrate having asperities on its surface,
the photosensitive resin coating is coated so as to conform to the
asperities, achieving high planarity. Further, if the
photosensitive resin coating is in close contact with the substrate
in a vacuum environment, generation of gaps therebetween is
effectively inhibited.
[0084] The photosensitive dry film may be manufactured by coating
the photosensitive resin composition to a support and drying the
resin composition into a resin coating. An apparatus for
manufacturing the photosensitive dry film may be a film coater
commonly used in the manufacture of pressure-sensitive adhesive
products. Suitable film coaters include, for example, a comma
coater, comma reverse coater, multiple coater, die coater, lip
coater, lip reverse coater, direct gravure coater, offset gravure
coater, three roll bottom reverse coater, and four roll bottom
reverse coater.
[0085] The support (film) is unwound from a supply roll in the film
coater, passed across the head of the film coater where the
photosensitive resin composition is coated onto the support to the
predetermined buildup, and then moved through a hot air circulating
oven at a predetermined temperature for a predetermined time, where
the photosensitive resin coating is dried on the support.
Thereafter, the support having the photosensitive resin coating
thereon and a protective film which is unwound from another supply
roll in the film coater are passed across a laminate roll under a
predetermined pressure whereby the protective film is bonded to the
photosensitive resin coating on the support, whereupon the laminate
(protective film-bearing photosensitive dry film) is wound up on a
take-up shaft in the film coater. Preferably, the oven temperature
is 25 to 150.degree. C., the pass time is 1 to 100 minutes, and the
bonding pressure is 0.01 to 5 MPa.
[0086] The support film used in the photosensitive dry film may be
a single film or a multilayer film consisting of a plurality of
stacked polymer layers. Examples of the film material include
synthetic resins such as polyethylene, polypropylene, polycarbonate
and polyethylene terephthalate (PET), with the PET film being
preferred for appropriate flexibility, mechanical strength and heat
resistance. These films may have been pretreated such as by corona
treatment or coating of a release agent. Such films are
commercially available, for example, Cerapeel.RTM. WZ(RX) and
Cerapeel.RTM. BX8(R) from Toray Advanced Film Co., Ltd.; E7302 and
E7304 from Toyobo Co., Ltd.; Purex.RTM. G31 and Purex.RTM. G71T1
from Teijin DuPont Films Japan Ltd.; and PET38.times.1-A3,
PET38.times.1-V8 and PET38.times.1-X08 from Nippa Co., Ltd.
[0087] The protective film used in the photosensitive dry film may
be similar to the support film. Among others, PET and polyethylene
films having an appropriate flexibility are preferred. Such films
are also commercially available. For example, PET films are as
mentioned above, and polyethylene films include GF-8 from Tamapoly
Co., Ltd. and PE film 0 type from Nippa Co., Ltd.
[0088] Both the support and protective films preferably have a
thickness of 10 to 100 .mu.m, more preferably 25 to 50 .mu.m, for
consistent manufacture of photosensitive dry film, and prevention
of wrapping or curling on a take-up roll.
Pattern Forming Process Using Photosensitive Dry Film
[0089] A further embodiment of the invention is a pattern forming
process comprising the steps of: [0090] (i') using the
photosensitive dry film to form the photosensitive resin coating on
a substrate, [0091] (ii) exposing the photosensitive resin coating
to radiation to define exposed and unexposed regions, [0092] (iii)
developing the exposed resin coating in a developer to dissolve
away the unexposed region of the resin coating and to form a
pattern of the resin coating.
[0093] In step (i'), the photosensitive dry film is used to form
the photosensitive resin coating on a substrate. Specifically, the
photosensitive dry film at its photosensitive resin coating is
attached to a substrate to form the photosensitive resin coating on
the substrate. When the photosensitive dry film is covered with the
protective film, the dry film at its photosensitive resin coating
is attached to a substrate after stripping the protective film
therefrom, to form the photosensitive resin coating on the
substrate. The dry film may be attached using a film attachment
apparatus.
[0094] Examples of the substrate include silicon wafers, TSV
silicon wafers, silicon wafers which have been thinned by back side
polishing, plastic substrates, ceramic substrates, and substrates
having a metal coating of Ni or Au wholly or partly on the surface
by ion sputtering or plating. Also useful are substrates having
grooves and/or holes having an opening width of 10 to 100 .mu.m and
a depth of 10 to 120 .mu.m.
[0095] The film attachment apparatus is preferably a vacuum
laminator. The photosensitive dry film is mounted in the film
attachment apparatus where the protective film is stripped from the
dry film. In the vacuum chamber kept at a predetermined vacuum, the
bare photosensitive resin coating of the dry film is closely bonded
to the substrate on a table at a predetermined temperature, using a
bonding roll under a predetermined pressure. Preferably, the
temperature is 60 to 120.degree. C., the pressure is 0 to 5.0 MPa,
and the vacuum is 50 to 500 Pa.
[0096] The attachment of dry film may be repeated plural times, if
necessary to obtain a photosensitive resin coating having the
desired thickness. The attachment step is repeated 1 to 10 times,
for example, before a photosensitive resin coating having a
thickness of the order of 10 to 1,000 .mu.m, preferably 100 to 500
.mu.m is obtained.
[0097] The assembly of the photosensitive resin coating on the
substrate may be prebaked, if necessary, for facilitating
photo-cure reaction of the photosensitive resin coating or
enhancing the adhesion between the resin coating and the substrate.
Prebake may be, for example, at 40 to 140.degree. C. for 1 minute
to 1 hour.
[0098] Like the pattern forming process using the photosensitive
resin composition, the photosensitive resin coating attached to the
substrate may be subjected to steps of (ii) exposing the
photosensitive resin coating to radiation, (iii) developing the
exposed resin coating in a developer to dissolve away the unexposed
region of the resin coating and to form a pattern of the resin
coating, and optionally (iv) post-curing the patterned coating. It
is noted that the support of the photosensitive dry film may be
removed before prebake or before PEB, by mechanical stripping or
the like, depending on a particular process.
[0099] The resin coating obtained from the photosensitive resin
composition or photosensitive dry film has excellent properties
including flexibility, pattern forming ability, electric
insulation, reliability as dielectric protective film, mechanical
properties, and substrate adhesion. The resin coating is thus best
suited as a protective film for electric and electronic parts such
as semiconductor devices and as a resist material for plating.
EXAMPLES
[0100] Examples of the invention are given below by way of
illustration and not by way of limitation. Notably, the weight
average molecular weight (Mw) is measured by gel permeation
chromatography (GPC) versus monodisperse polystyrene standards
using GPC column TSKgel Super HZM-H (Tosoh Corp.) under analytical
conditions: flow rate 0.6 mL/min, tetrahydrofuran elute, and column
temperature 40.degree. C. All parts are by weight (pbw).
[0101] The compounds used in polymer synthesis are shown below.
##STR00012##
[1] Synthesis of Polymers
Example 1-1
[0102] Synthesis of Resin 1
[0103] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 156.8 g (0.40 mol)
of the compound having formula (S-1), 53.9 g (0.10 mol) of the
compound having formula (S-3a) (UNIOX from NOF Corp.), and 2,000 g
of toluene and heated at 70.degree. C. Thereafter, 1.0 g of a
toluene solution of chloroplatinic acid (platinum concentration 0.5
wt %) was added, and 97.0 g (0.50 mol) of the compound having
formula (S-5) was added dropwise over 1 hour. The ratio of the
total moles of hydrosilyl groups to the total moles of alkenyl
groups was 1/1. At the end of dropwise addition, the reaction
solution was heated at 100.degree. C. and aged for 6 hours. Toluene
was distilled off in vacuum from the reaction solution, yielding
Resin 1. Resin 1 had a Mw of 43,000. On .sup.1H-NMR spectroscopy
(Bruker Corp.), Resin 1 was identified to be a polymer containing
repeating units (1) and (2).
Example 1-2
[0104] Synthesis of Resin 2
[0105] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 172.0 g (0.40 mol)
of the compound having formula (S-7), 53.9 g (0.10 mol) of the
compound having formula (S-3a), and 2,000 g of toluene and heated
at 70.degree. C. Thereafter, 1.0 g of a toluene solution of
chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 97.0 g (0.50 mol) of the compound having formula (S-5) was
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 2. Resin 2 had a
Mw of 25,000. On .sup.1H-NMR spectroscopy (Bruker Corp.), Resin 2
was identified to be a polymer containing repeating units (1) and
(3).
Example 1-3
[0106] Synthesis of Resin 3
[0107] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 106.0 g (0.40 mol)
of the compound having formula (S-2), 53.9 g (0.10 mol) of the
compound having formula (S-3a), and 2,000 g of toluene and heated
at 70.degree. C. Thereafter, 1.0 g of a toluene solution of
chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 97.0 g (0.50 mol) of the compound having formula (S-5) was
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 3. Resin 3 had a
Mw of 34,000. On .sup.1H-NMR spectroscopy (Bruker Corp.), Resin 3
was identified to be a polymer containing repeating units (1) and
(4).
Example 1-4
[0108] Synthesis of Resin 4
[0109] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 9.8 g (0.025 mol)
of the compound having formula (S-1), 10.8 g (0.025 mol) of the
compound having formula (S-7), 13.3 g (0.05 mol) of the compound
having formula (S-2), and 215.6 g (0.40 mol) of the compound having
formula (S-3a), and then with 2,000 g of toluene and heated at
70.degree. C. Thereafter, 1.0 g of a toluene solution of
chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 97.0 g (0.50 mol) of the compound having formula (S-5) was
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 4. Resin 4 had a
Mw of 50,000. On .sup.1H-NMR spectroscopy (Bruker Corp.), Resin 4
was identified to be a polymer containing repeating units (1), (2),
(3), and (4).
Example 1-5
[0110] Synthesis of Resin 5
[0111] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 9.8 g (0.025 mol)
of the compound having formula (S-1), 10.8 g (0.025 mol) of the
compound having formula (S-7), 13.3 g (0.05 mol) of the compound
having formula (S-2), and 327.2 g (0.40 mol) of the compound having
formula (S-3b), and then with 2,000 g of toluene and heated at
70.degree. C. Thereafter, 1.0 g of a toluene solution of
chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 97.0 g (0.50 mol) of the compound having formula (S-5) was
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 5. Resin 5 had a
Mw of 58,000. On .sup.1H-NMR spectroscopy (Bruker Corp.), Resin 5
was identified to be a polymer containing repeating units (1), (2),
(3), and (4).
Comparative Example 1-1
[0112] Synthesis of Resin 6
[0113] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 196.0 g (0.50 mol)
of the compound having formula (S-1) and then 2,000 g of toluene
and heated at 70.degree. C. Thereafter, 1.0 g of a toluene solution
of chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 87.3 g (0.45 mol) of the compound having formula (S-5) and 79.3
g (0.05 mol) of the compound having formula (S-6) wherein y=20 were
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 6. Resin 6 had a
Mw of 41,000.
Comparative Example 1-2
[0114] Synthesis of Resin 7
[0115] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 215.0 g (0.50 mol)
of the compound having formula (S-7) and then 2,000 g of toluene
and heated at 70.degree. C. Thereafter, 1.0 g of a toluene solution
of chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 48.5 g (0.25 mol) of the compound having formula (S-5) and
396.3 g (0.25 mol) of the compound having formula (S-6) wherein
y=20 were added dropwise over 1 hour. The ratio of the total moles
of hydrosilyl groups to the total moles of alkenyl groups was 1/1.
At the end of dropwise addition, the reaction solution was heated
at 100.degree. C. and aged for 6 hours. Toluene was distilled off
in vacuum from the reaction solution, yielding Resin 7. Resin 7 had
a Mw of 31,000.
Comparative Example 1-3
[0116] Synthesis of Resin 8
[0117] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 132.5 g (0.50 mol)
of the compound having formula (S-2) and then 2,000 g of toluene
and heated at 70.degree. C. Thereafter, 1.0 g of a toluene solution
of chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 77.6 g (0.40 mol) of the compound having formula (S-5) and
158.5 g (0.10 mol) of the compound having formula (S-6) wherein
y=20 were added dropwise over 1 hour. The ratio of the total moles
of hydrosilyl groups to the total moles of alkenyl groups was 1/1.
At the end of dropwise addition, the reaction solution was heated
at 100.degree. C. and aged for 6 hours. Toluene was distilled off
in vacuum from the reaction solution, yielding Resin 8. Resin 8 had
a Mw of 44,000.
Comparative Example 1-4
[0118] Synthesis of Resin 9
[0119] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 9.8 g (0.025 mol)
of the compound having formula (S-1), 10.8 g (0.025 mol) of the
compound having formula (S-7), 13.3 g (0.05 mol) of the compound
having formula (S-2) and 74.4 g (0.40 mol) of the compound having
formula (S-4) and then with 2,000 g of toluene and heated at
70.degree. C. Thereafter, 1.0 g of a toluene solution of
chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 97.0 g (0.50 mol) of the compound having formula (S-5) was
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 9. Resin 9 had a
Mw of 39,000.
Comparative Example 1-5
[0120] Synthesis of Resin 10
[0121] A 3-L flask equipped with a stirrer, thermometer, nitrogen
purge line and reflux condenser was charged with 78.4 g (0.20 mol)
of the compound having formula (S-1), 43.0 g (0.10 mol) of the
compound having formula (S-7), and 53.0 g (0.20 mol) of the
compound having formula (S-2) and then with 2,000 g of toluene and
heated at 70.degree. C. Thereafter, 1.0 g of a toluene solution of
chloroplatinic acid (platinum concentration 0.5 wt %) was added,
and 97.0 g (0.50 mol) of the compound having formula (S-5) was
added dropwise over 1 hour. The ratio of the total moles of
hydrosilyl groups to the total moles of alkenyl groups was 1/1. At
the end of dropwise addition, the reaction solution was heated at
100.degree. C. and aged for 6 hours. Toluene was distilled off in
vacuum from the reaction solution, yielding Resin 10. Resin 10 had
a Mw of 29,000.
[2] Preparation and Evaluation of Photosensitive Resin
Composition
Examples 2-1 to 2-11 and Comparative Examples 2-1 to 2-10
[0122] Photosensitive resin compositions of Examples 2-1 to 2-11
and Comparative Examples 2-1 to 2-10 were prepared by combining the
resin (Resins 1 to 10), photoacid generator, crosslinker, solvent,
and quencher in accordance with the formulation shown in Tables 1
and 2, agitating them at room temperature until dissolution, and
precision filtering through a Teflon.RTM. filter with a pore size
of 1.0 .mu.m.
TABLE-US-00001 TABLE 1 Component Example (pbw) 2-1 2-2 2-3 2-4 2-5
2-6 2-7 2-8 2-9 2-10 2-11 (A) Resin Resin 1 100 100 Resin 2 100
Resin 3 100 100 Resin 4 100 100 100 100 Resin 5 100 100 (B)
Photoacid PAG-1 1 1 1 1 1 1 1 5 1 1 1 generator (C) Crosslinker
CL-1 10 10 10 10 CL-2 10 10 10 10 (D) Solvent cyclopentanone 55 55
55 55 55 55 55 55 55 55 55 (E) Quencher AM-1 0.2
TABLE-US-00002 TABLE 2 Component Comparative Example (pbw) 2-1 2-2
2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 (A) Resin Resin 6 100 Resin 7 100
Resin 8 100 100 Resin 9 100 100 100 Resin 10 100 100 100 (B)
Photoacid PAG-1 1 1 1 1 1 1 1 1 5 1 generator (C) Crosslinker CL-1
10 CL-2 10 10 10 10 (D) Solvent cyclopentanone 55 55 55 55 55 55 55
55 55 55 (E) Quencher AM-1 0.2
[0123] In Tables 1 and 2, photoacid generator PAG-1, crosslinkers
CL-1 and CL-2, and quencher AM-1 are identified below.
##STR00013##
(1) Pattern Formation and Evaluation
[0124] A die coater was used as the film coater and a polyethylene
terephthalate (PET) film of 38 .mu.m thick used as the support.
Each of the photosensitive resin compositions of Examples 2-1 to
2-11 and Comparative Examples 2-1 to 2-10 was coated onto the
support. The coated support was passed through a hot air
circulating oven (length 4 m) set at 100.degree. C. over 5 minutes
for drying to form a photosensitive resin coating on the support,
yielding a photosensitive dry film. Using a laminating roll, a
polyethylene film of 50 .mu.m thick as the protective film was
bonded to the photosensitive resin coating under a pressure of 1
MPa, yielding a protective film-bearing photosensitive dry film.
The thickness of each to photosensitive resin coating is tabulated
in Tables 3 and 4. The thickness of a resin coating was measured by
an optical interference film thickness gauge.
[0125] From the protective film-bearing photosensitive dry film,
the protective film was stripped off. Using a vacuum laminator
TEAM-100RF (Takatori Corp.) with a vacuum chamber set at a vacuum
of 80 Pa, the photosensitive resin coating on the support was
closely bonded to a silicon substrate having copper sputter
deposited on its surface to a thickness of 400 nm. The temperature
was 110.degree. C. After restoration of atmospheric pressure, the
substrate was taken out of the laminator, and the support was
stripped off. Then the photosensitive resin coating was prebaked on
a hot plate at 130.degree. C. for 5 minutes for enhancing adhesion
to the substrate.
[0126] Next, using a contact aligner exposure tool, the
photosensitive resin coating was exposed to radiation of 405 nm
through a mask having a line-and-space pattern and a contact hole
pattern. After exposure, the coated substrate was baked (PEB) on a
hot plate at 120.degree. C. for 5 minutes and cooled. This was
followed by spray development in propylene glycol monomethyl ether
acetate (PGMEA) for 300 seconds for forming a pattern of the resin
coating.
[0127] The patterned photosensitive resin coating on the substrate
was post-cured in an oven at 180.degree. C. for 2 hours while the
oven was purged with nitrogen. Under a scanning electron microscope
(SEM), the contact hole patterns of 300 .mu.m, 200 .mu.m, 100
.mu.m, 80 .mu.m, and 60 .mu.m were observed in cross section, with
the minimum hole pattern in which holes extended down to the film
bottom being reported as maximum resolution. From the
cross-sectional photo, the contact hole pattern of 80 .mu.m was
evaluated for perpendicularity, and rated "Excellent (Exc.)" for
perpendicular pattern, "Good" for slightly inversely tapered
profile, "Fair" for inversely tapered profile, and "Poor" for
opening failure.
(2) Evaluation of Electric Properties (Dielectric Breakdown
Strength)
[0128] For the evaluation of dielectric breakdown strength of a
photosensitive resin coating of a photosensitive resin composition,
each of the photosensitive resin compositions of Examples 2-1 to
2-11 and Comparative Examples 2-1 to 2-10 was coated onto a steel
plate of 13 cm.times.15 cm.times.0.7 mm (thick) by means of a bar
coater and heated in an oven at 180.degree. C. for 2 hours to form
a photosensitive resin coating. The resin composition was coated
such that the resulting coating had a thickness of 0.2 .mu.m. The
resin coating was tested by a breakdown tester TM-5031AM (Tama
Densoku Co., Ltd.) to determine the dielectric breakdown strength
thereof.
(3) Evaluation of Reliability (Adhesion, Crack Resistance)
[0129] Each of the photosensitive resin coating-bearing substrates
after pattern formation and post-cure in Test (1) was cut into
specimens of 10 mm squares using a dicing saw with a dicing blade
(DAD685 by DISCO Co., spindle revolution 40,000 rpm, cutting rate
20 mm/sec). Ten specimens for each Example were examined by a
thermal cycling test (test of holding at -25.degree. C. for 10
minutes and holding at 125.degree. C. for 10 minutes, the test
being repeated 1,000 cycles). After the test, it was observed
whether or not the resin coating peeled from the substrate and
whether or not the resin coating cracked. The sample was rated
"Good" when all specimens did not peel or crack, "Peeled" when one
or more specimens peeled, and "Cracked" when one or more specimens
cracked.
[0130] The results are shown in Tables 3 and 4.
TABLE-US-00003 TABLE 3 Example 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9
2-10 2-11 Resin coating thickness (.mu.m) 302 305 298 297 303 301
299 301 300 302 305 Contact hole pattern profile Exc. Exc. Exc.
Exc. Good Good Good Good Exc. Exc. Exc. Maximum resolution (.mu.m)
60 60 60 60 80 80 80 100 60 60 60 Dielectric breakdown 815 810 800
810 700 715 720 720 805 820 815 strength (V/.mu.m) Reliability
Peeled or not Good Good Good Good Good Good Good Good Good Good
Good Cracked or not Good Good Good Good Good Good Good Good Good
Good Good
TABLE-US-00004 TABLE 4 Comparative Example 2-1 2-2 2-3 2-4 2-5 2-6
2-7 2-8 2-9 2-10 Resin coating thickness (.mu.m) 298 302 303 299
303 301 304 299 298 300 Contact hole pattern profile Fair Fair Fair
Fair Fair Fair Fair Fair Fair Fair Maximum resolution (.mu.m) 300
300 300 300 300 300 300 300 300 300 Dielectric breakdown 490 520
510 515 530 495 500 520 525 540 strength (V/.mu.m) Reliability
Peeled or not Peeled Peeled Peeled Peeled Peeled Peeled Peeled
Peeled Peeled Peeled Cracked or not Cracked Cracked Cracked Cracked
Cracked Cracked Cracked Cracked Cracked Cracked
[0131] As is evident from the test results, the photosensitive
resin compositions of Examples 2-1 to 2-11 within the scope of the
invention experience little film thickness loss, exhibit good
resolution, i.e., sufficient properties as photosensitive material.
The cured resin coatings obtained therefrom have improved electric
properties (e.g., dielectric breakdown strength), and improved
adhesion and crack resistance after the thermal cycling test, and
are thus useful as protective film for circuits and electronic
parts. Thus photosensitive dry films having more reliability are
available.
(4) Evaluation as Resist Material for Plating
[0132] The photosensitive resin compositions of Examples 2-1 to
2-11 were examined for their performance as a resist material for
plating.
[0133] From the protective film-bearing photosensitive dry film
prepared by the same procedure as in (1), the protective film was
stripped off. Using a vacuum laminator TEAM-100RF (Takatori Corp.)
with a vacuum chamber set at a vacuum of 80 Pa, the photosensitive
resin coating on the support was closely bonded to a silicon
substrate having copper sputter deposited on its surface to a
thickness of 400 nm. The temperature was 110.degree. C. After
restoration of atmospheric pressure, the substrate was taken out of
the laminator, and the support was stripped off. Then the
photosensitive resin coating was prebaked on a hot plate at
130.degree. C. for 5 minutes for enhancing adhesion to the
substrate.
[0134] Next, using a contact aligner exposure tool, the
photosensitive resin coating was exposed to radiation of 405 nm
through a mask having a line-and-space pattern and a contact hole
pattern. After exposure, the coated substrate was baked (PEB) on a
hot plate at 120.degree. C. for 5 minutes and cooled. This was
followed by spray development in PGMEA for 300 seconds for forming
a pattern of the resin coating. The pattern-bearing substrate was
immersed in a copper plating bath (Microfab Cu200, Electroplating
Engineers of Japan Ltd.), where electroplating of copper was
carried out at a constant current flow. In Examples 2-1 to 2-11,
Cu-plating posts were properly formed, without stripping of the
resin coating. It is demonstrated that the photosensitive resin
compositions are also useful as a resist material for plating.
[0135] Japanese Patent Application No. 2018-095370 is incorporated
herein by reference.
[0136] Although some preferred embodiments have been described,
many modifications and variations may be made thereto in light of
the above teachings. It is therefore to be understood that the
invention may be practiced otherwise than as specifically described
without departing from the scope of the appended claims.
* * * * *